Several investigations performed throughout the years regarding the failures of bearings used in a variety of applications have shown that in a very large population (several million bearings), the observed failures are a relatively rare event and not directly related to typical raceway spalling. This shows that the design guidelines based on 90% reliability and the use of static and dynamic safety factors can lead to robust bearing solutions in which typical fatigue failures are in general avoided. Indeed, observed field failures are mostly related to abrasive wear, moisture, corrosion, improper mounting, improper shaft/housing fits, skidding of rolling elements, unforeseen contamination.